I just built a log splitter and I'm temporarily powering it with my Bobcat until I get all the kinks worked out with the 4-way wedge. I figured the Bobcat would have more hyd power than the little Haldex 2-stage pumps, but it appears as it doesn't. Has anyone had the same dealings with this? Could it be that the 2-stage pumps put out more power than my std. flow 773? Also does it matter they way you hook the hydralic lines into the cylinder, it seems like the cylinder gets very warm after a very short use. I just can't believe a 5hp briggs puts out more hyd. power than a Skidsteer. Any comments much appreciated. Thanks
Help Support SkidSteer Forum:
skidsteer.ca
Well-known member
- Joined
- Jan 20, 2006
- Messages
- 3,853
It depends on how you define power. Asuming all things are working as they should. Your 773 has 16.9 gpm at 3000 psi
The haldex pump MAY have more volume at a lower psi. So this means whenn the splitter is not under load it can move the cylinder faster. ( if this is true) However your loader will definitely have more flow when the going gets tough for the splliter
I'm not sure at what psi these pumps switch from hi flow to low flow and if this occurs the moment the wedge touches the wood or if some wood splits so easy that the pump stays on the high volume side during the split or a portion of it.
I have a spitter with a 4" by 24 cylinder, it works best on my NH ls 160 that has 15 gpm on low flow and 24 gpm on high flow, On high flow I can run the engine about 2000 or 2100 and still get a decent speed on the cylinder, I have used it vary little as I just got it last spring, but the temptation is there to run the rpm higher yet
Hydraulic oil will quickly warm to 120 and levels off @ 130 degrees in our 75 degree ambient temps but if your splitter cylinder is getting too hot to touch for more then a second or two (generally that means over 140 or 150 degrees then you may have other problems.
If you have too small or lines in your system or other restrictions or you are contantly bottoming out the cylinder or the cylinder is too small (which means its faster but has less power) and it is stopping because the relief pressure is being reached, these will all heat the oil, but a bobcat does have a prety good oil cooler, for our climate anyway.
Are you using a manual valve at the splitter or are you running your cylinder from inside the cab? What is the bore on your cylinder 4" ??
5" would be overkill for the wood I split, and would slow the splitter considerably by greatly increasing the volume of oil required to fill the cylinder, although it would have tremendous force
Ken
The haldex pump MAY have more volume at a lower psi. So this means whenn the splitter is not under load it can move the cylinder faster. ( if this is true) However your loader will definitely have more flow when the going gets tough for the splliter
I'm not sure at what psi these pumps switch from hi flow to low flow and if this occurs the moment the wedge touches the wood or if some wood splits so easy that the pump stays on the high volume side during the split or a portion of it.
I have a spitter with a 4" by 24 cylinder, it works best on my NH ls 160 that has 15 gpm on low flow and 24 gpm on high flow, On high flow I can run the engine about 2000 or 2100 and still get a decent speed on the cylinder, I have used it vary little as I just got it last spring, but the temptation is there to run the rpm higher yet
Hydraulic oil will quickly warm to 120 and levels off @ 130 degrees in our 75 degree ambient temps but if your splitter cylinder is getting too hot to touch for more then a second or two (generally that means over 140 or 150 degrees then you may have other problems.
If you have too small or lines in your system or other restrictions or you are contantly bottoming out the cylinder or the cylinder is too small (which means its faster but has less power) and it is stopping because the relief pressure is being reached, these will all heat the oil, but a bobcat does have a prety good oil cooler, for our climate anyway.
Are you using a manual valve at the splitter or are you running your cylinder from inside the cab? What is the bore on your cylinder 4" ??
5" would be overkill for the wood I split, and would slow the splitter considerably by greatly increasing the volume of oil required to fill the cylinder, although it would have tremendous force
Ken
The log splitter pump I'm using is a 16 gpm, The cylinder is a 4x24 with 1/2" lines going to the cylinder as that is what the port sizes are on the cylinder, I was using the controls in the Bobcat to operate the splitter. I was wanting to try everything out before I did more work to find out that something wasn't working like I wanted with the 4-way wedge, and I'm glad I did because it didn't... I would guess from how you described the cylinder temps it was probably normal, I was just surprised on how fast it got that warm. Here is the splitter I made it is posted in another site but that is the story. Asking you guys that work with more hyd. what would you think from what you can see, what/how big of pump motor would I need to get this to work out? http://www.arboristsite.com/showthread.php?t=72930 Thanks Frank
Impressive!
skidsteer.ca
Well-known member
- Joined
- Jan 20, 2006
- Messages
- 3,853
How many seconds does it take to make a full cycle at "no load" now? And how long if your splitting something?
You don't have a 3000 psi guage you can hook in to see how high your pressure does get when splitting, and when you bottom the cylinder out and force the relief valve open? That is about the only way to be sure your getting the power you should get.
If I get time I'll check mine with a watch to see the times. Forget what the small engine splitters rate theirs at, but I'm thinking 11 to 16 seconds full cycle?? (mine seems a bit slower then that)
You know your flow now, its just a matter of checking the cycle time and calculating how fast you want it?
If I could have my 24 gpm at 2000 rpm (instead of 3000) I think that would be about right. I don't run it that fast so I have about 16 gpm at 2/3 throttle (2000 rpm) Its not painfully slow, but was less then I thought.
Ken
skidsteer.ca
Well-known member
- Joined
- Jan 20, 2006
- Messages
- 3,853
Here are some hyd calculators
http://www.baumhydraulics.com/pages.php?pageid=4
Not sure how the small 5.5 hp splitters get 20 tons plus with a 4" ram, acording to these folks that takes 3183.1 psi to get 20 tons
Here is the speed of a 4" cylinder using their calculators using the flow your 773 should have.
btw what year is your 773? most had that pump size, some of the f series may have been smaller flows.
| Simply Complete These Four Columns: | ||||
| Pump GPM | Cylinder Bore(inch) | Stroke (inch) | Rod Diameter (inch) | Extend speed Retract speed |
| | | | |
| ||||
No I don't have gauge on it, but I can. I haven't timed the cycle of it, i was so disgusted by what it wouldn't do that I haven't looked at what it will do. I agree I don't understand how how this 5hp honda motors are putting out 27 ton splitters, I think there is something fishy about that!! If I would have ot guess I would say the cycle times is between 10-15 sec. at WOT. I have a 2000 773G. I would think that Hyd. are fine on it, every attachment I've run has done fine even the stump grinder, it was a little slow but it wasn't really made for a std. flow machine and it showed. Maybe I was just expecting more because it's bigger, I guess I underestimated the power of the little log splitters capabilities. I will get some numbers and maybe hook up my control valve and put a pressure gauge in it before to long. Thanks for that great website. Frank
